Fuel-burning fireplace

ABSTRACT

A burner system for a fuel-burning fireplace having a fuel container with at least one aperture for combusting the fuel contained therein and an adjustable flame regulator for regulating a size of the flame. The flame regulator comprises a shutter for covering the aperture having a shape corresponding to the aperture, the shutter being variably adjustable between a first position (covered aperture) and a second position (exposed aperture); a handle extending from the burner system for variably adjusting the shutter; and a connecting member for connecting the shutter to the handle, the connecting member being secured to at least two extremities of the shutter; wherein movement of the handle allows a balanced movement of the shutter over the aperture.

TECHNICAL FIELD

This invention relates generally to fuel-burning fireplaces. More specifically, this invention relates to systems and devices for variably adjusting a flame size and controlling a combustion rate.

BACKGROUND

Fuel-burning fireplaces, such as ethanol-burning fireplaces, offer clean and energy efficient heating of an environment. Indeed, the energy efficiency arises at least partially because venting to the outside is not required with such fireplaces due to the discharge of only water vapor and small quantities carbon dioxide. Furthermore, fuel-burning fireplaces create ambiance in an environment by providing an elegant flame that resembles that of a classic wood-burning fireplace.

Jensen (U.S. Pat. No. 8,434,470) teaches a fuel-burning fireplace with an adjustable burn apparatus. The fuel container has a cover with a slidably adjustable shutter secured to its lower surface. A user of the fireplace that wishes to adjust the flame uses a hook tool that is separate from but functionally connectable to the shutter in order to manipulate hot portions of the container.

Applicant's prior adjustable shutter system was made with a handle connected to one central location on a shutter that allowed variable control of a flame by appropriately positioning the shutter over the fuel container aperture. The handle is located at a level of the flame aperture and thus requires getting relatively close the source of heat. Translational movement of the handle connected to a central location of the shutter provides an unbalanced movement of the shutter.

In U.S. Pat. No. 5,906,197, French et al. teach that fuel-burning fireplaces typically comprise room air plenums below, above and adjacent the sides and/or rear of the firebox. A convection current is created whereby room air is pulled into the bottom plenum, passes upwardly in the side and/or rear plenums into the top plenum and thereafter exits the fireplace from the top plenum. As the room air circulates around the firebox, heat is transferred from the firebox to the circulating room air so that the temperature of the air exiting the top plenum, has substantially increased in the process. The French et al. fireplace has a closed-flame firebox design where a protective glass panel isolates the flame from the environment and where the heating capability is mainly due to the heat released from the convection chamber.

In US Pat. Appl. No. 2012/0260905, Jensen teaches a protective glass for a fuel-burning fireplace that is supported by a slot defined inside the burner system. In such a configuration, the protective glass is in direct contact with the source of heat.

Some of the drawbacks of current fuel-burning fireplaces are their short burn times and fuel refilling requirements. Refilling the fuel container can be dangerous for the user of a fireplace and therefore reducing the frequency of refilling by increasing burn time decreases the danger associated with a fuel-burning fireplace.

Other drawbacks of current systems include flame shutters that require a user getting dangerously close to the flame, which is almost invisible when a fuel container is nearly empty and the flame is about to extinguish. There is therefore a need for a fuel-burning fireplace that avoids the above shortcomings.

SUMMARY

Applicant has discovered a new fuel-burning fireplace that addresses the above shortcomings and provides a fireplace with a burner system comprising a fuel container having at least one aperture for combusting the fuel contained therein; and an adjustable flame regulator for regulating a size of the flame comprising; a shutter for covering the aperture having a shape corresponding to the aperture, the shutter being variably adjustable between a first position wherein the aperture is covered and a second position wherein the aperture is exposed; a handle extending from the burner system for variably adjusting the shutter; and a connecting member for connecting the shutter to the handle, the connecting member being secured to at least two extremities of the shutter; wherein movement of the handle allows a balanced movement of the shutter over the aperture.

In some aspects, the connecting member rests on the top surface and slides across the aperture. It may be configured such that a lateral movement of the handle with respect to the fireplace causes a longitudinal movement of the shutter.

In some aspects, the connecting member is rotatably mounted to each of the extremities of the container and rotates around a first rotational axis defined along the two extremities.

In other aspects, the shutter has apertures at/near its extremities for receiving an extension of the connecting member, the extension extending from the connecting member at/near the first rotational axis.

In yet other aspects, the handle is rotatably mounted to the container and wherein the rotational axis is orthogonal to the first axis and causes a rotation of the connecting member around the second rotational axis.

In some embodiments, the burner system comprises a coverplate for covering the container and the shutter.

In some embodiments, the coverplate comprises slits for allowing a proper air intake at a site of combustion and for evacuating gaseous fuel accumulation and preventing “poufs” upon ignition of the flame.

In some embodiments, the coverplate comprises apertures at its extremities for receiving the connecting member extension, wherein the shutter is adjustable by the extension.

According to another embodiment, there is provided a fuel-burning fireplace comprising a burner for combusting a liquid fuel; an inner housing for receiving heat from the burner system; and an outer housing fitting around the inner housing and defining a convection chamber between the inner housing and the outer housing; wherein the chamber comprises air intake apertures on a bottom for receiving colder air into the chamber and air outflow apertures on a top for releasing warmer air form the chamber while cooling a surface of the outer housing.

In some aspects, the fireplace comprises one or more glass receiving member extending from the outer housing, the glass receiving member comprising a slot for receiving and securing a protective glass without making holes in the glass.

According to yet another embodiment, a burner for a liquid fuel burning fireplace comprises a fuel container having a top surface with an aperture for allowing a combustion of fuel contained therein and generating a flame; a flap adjacent and along a side of the aperture and extending away from the top surface toward an inside of the container; the flap having flap apertures therein configured to slow combustion of the fuel and animate the flame by creating turbulence.

In some aspects, the flap is continuous with the top surface and represents a portion of the top surface that was in place of the aperture prior to bending the flap.

In some aspects, the flap aperture diameter (or diagonal) is between 4 and 6 mm.

In some aspects, the surface area of the flap apertures is between 100% to 80% of the total surface area of the flap but preferably between 20 and 40% and even more preferably around 25%.

In some aspects, the top surface is a removable coverplate

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be better understood by way of the following detailed description of embodiments of the invention with reference to the appended drawings, in which:

FIG. 1 is an illustration of an ethanol-burning fireplace according to an embodiment of the present invention.

FIG. 2A shows a burner system according to an embodiment of the present invention and FIG. 2B shows the burner system of FIG. 2A inside a fireplace housing.

FIG. 3 is an exploded view of the fireplace housing according to an embodiment of the present invention.

FIG. 4 is an exploded view of the burner system according to an embodiment of the present invention

FIG. 5 is a photograph of a burner system according to an embodiment of the present invention viewed from underneath in order to see the adjustable flame regulator.

FIG. 6 shows a top surface of a fuel container for a fuel-burning fireplace where FIG. 6A shows a top view of the top surface having an aperture therein. FIG. 6B shows a side view of the top surface showing multiple flaps bent and extending downward toward an inside of a container. FIG. 6C shows a top perspective view of a top surface with the flap extending downward into the container (not shown).

FIG. 7 shows and embodiment of an adjustable shutter for a burner system having a direct longitudinal shutter adjustment translation based movement.

FIG. 8 shows the movement of air in a convection area of a fuel burning fireplace according to and embodiment of the present invention.

FIG. 9 shows a partially exploded view of the various parts of a fuel-burning fireplace according to an embodiment of the present invention.

DETAILED DESCRIPTION

FIG. 1 is an illustration of an ethanol-burning fireplace 10 according to an embodiment of the present invention. Although the embodiment shown is a designed to be mounted to a wall 19, it will be appreciated that a free-standing fireplace unit will be similar in many ways, except for such structural elements as a back outer surface on both the inner and outer housings and the mounting member for mounting the fireplace to a wall (as shown in FIG. 3). FIG. 1 shows an ethanol-burning fireplace 10 having an outer housing 14 having an outer housing frame 17 having a glass receiving member 16 extending therefrom. In this embodiment, the glass receiving member 16 extends from the outer housing frame 17 and the frame is considered part of the outer housing. The glass receiving member 16 can also extend directly from the outer housing 14. The glass receiving member 16 is designed for supporting/securing in place a front protective glass 19. One of the main advantages of the glass receiving member 16 is that by having slot, it can receive and secure a protective glass 19 without having holes made in the protective glass 19. Avoiding holes in the protective glass 19 is important for the structural integrity of the glass which is subjected to many heat-cold cycles. Combustion of specially formulated ethanol fuels, for example, allows the fireplace to generate a flame 11, that, in many ways, resembles the flame obtained in a wood burning fireplace. The flame obtained from the combustion of ethanol is “cleaner” than that obtained from the combustion of wood. This explains why, in many cases, venting of an ethanol-burning fireplace to the outside is not required, as would be the case for a wood-burning fireplace. The fireplace 10 has a handle 12 for variably adjusting the size of a flame 11. Adjusting the size of the flame is understood as including extinguishing the flame completely using a mechanism connected to the handle 12.

FIG. 2A shows a burner system 20 according to an embodiment of the present invention. The burner system 20 is designed to fit inside the fireplace 10. FIG. 2B shows the burner system 20 inside the fireplace 10. The handle 12 for variably adjusting the size of the flame 11 extends from the burner system. A coverplate 24 is for covering the fuel container 58. The coverplate 24 has an aperture therein designed to functionally correspond to aperture 40 (shown in FIG. 4) located just underneath.

FIG. 2B shows the burner system 20 of FIG. 2A inside a fuel-burning fireplace 10. The fireplace 10 has an outer housing 14 and a handle 12 extending from a front surface thereof. Although the protective glass is not shown in FIG. 2B, the glass receiving member 16 extends from the outer housing frame 17. In addition to having apertures to allow an air outflow from the outer housing 14 and supporting the glass receiving member 16, the outer housing frame 17 serves essentially an aesthetic purpose.

FIG. 3 is an exploded view of the fireplace housing (excludes the burner system) according to an embodiment of the present invention. The leftmost element of FIG. 3 is the protective glass 19 which is secured to or supported by the glass receiving member 16, itself extending from the outer housing frame 17. The outer housing 14 has an outer housing top surface 15. The fireplace has a burner system support member 31 which is used to support the burner system 20 of FIG. 2A. The inner housing is defined by inner housing side walls 32, an inner housing top surface 33, an inner housing back surface 37, and the bottom is defined by the burner system 20 and the burner system support member 31. The outer housing bottom surface 35 has holes to allow air intake from underneath the fireplace for convective cooling of the fireplace (see FIG. 8). The outer housing also has an outer housing back surface 36 which can made of a different material than the outer housing 14 because the outer housing back surface 36 is not visible in a wall mounted unit. It will be appreciated that the inner housing and outer housing can be manufactured as a single part defining a chamber therein that is in contact with the heat producing element. It will also be appreciated that fuel burning fireplaces are typically made of metal products, such as stainless steel, due to their structural, aesthetic and heat-resistant properties but any material that can demonstrate these properties is appropriate for the manufacture of a fireplace according to the present invention.

FIG. 4 is an exploded view of a burner system 20 according to an embodiment of the present invention. The fuel container 58 is for receiving and containing fuel for combustion for generating a hot flame 11. The fuel container 58 has a fuel container top surface 41 that has an aperture 40 therein for allowing fuel contained therein to evaporate from inside the container and come into contact with oxygen to initiate a combustion reaction. The top surface 41 is modified in combination with the aperture 40 to increase the efficiency of combustion and to allow for longer combustion periods between refilling the container. The fuel container 58 is combined with an adjustable flame regulator comprising a shutter 42 for variably adjusting a flame 11 by covering a portion of the aperture 40. In the embodiment illustrated, the shutter 42 is moved over the aperture 40 by moving the handle 12 in an essentially lateral direction with respect to the fireplace. The longitudinal movement of shutter 42 over aperture 40 induced by the lateral movement of handle 12 is permitted by the connecting member 46 which is designed to be rotationally secured to two extremities 48 of the fuel container 58 at one end to rotate about a first rotational axis 45 and on a first end functionally coupled to a converter member 50 which rotates about a second rotational axis 55 being orthogonal to the first rotational axis and on a second end functionally coupled to the shutter 42. Functional coupling of the connecting member 46 is achieved at both ends by having a connecting member extension 49 which is upwardly extending and passes through a shutter aperture 47 at the first end and a downwardly extending extension passing through a converter member 50 aperture. The connecting member 46 comprises end portions that are secured to the fuel container extremities and a connecting portion that allows to connect the two end portions. The coverplate 43 also comprises slits 44 defined therein for allowing an exchange of air for combustion and for preventing “poufs” associated with ignition of small accumulations (pockets) of gaseous fuel. The coverplate 43 also comprises coverplate apertures 51 at its extremities for receiving a connecting member extension 49. The connecting member extension 49 can be handled by a user of the fireplace instead of the handle 12 to adjust the shutter when the fireplace is not or has not been active for some time. The burner system also comprises an overflow container 52 which can be advantageously manufactured by folding an appropriate piece of metal and by welding an overflow container side member 59 at the two lateral extremities. The overflow container 52 should advantageously be designed to contain a volume of liquid fuel equivalent to 10% of the fuel container 58 capacity.

FIG. 5 is a photograph of a burner system according to the embodiment shown in FIG. 4 and viewed from underneath in order to see the adjustable flame regulator. The coverplate 43 and the coverplate aperture 51 are shown at the top. The first rotational axis 45 is where the connecting member 46 rotates around an axis extending from two extremities of the fuel container 58. The connecting member 46 has a connecting member extension 49 that extends upwardly and passes through the coverplate aperture 51 in order to variably adjust the coverplate 43 over the aperture 40 (shown in FIG. 4) when the connecting member 46 is caused to rotate about the first rotational axis 45. The second rotational axis 55 extends along an axis that is orthogonal to the first rotational axis 45 and is secured to an underside of the overflow container 52. The converter member 50 is responsible for converting a lateral movement of a handle 12 into a longitudinal movement of the shutter 42. It will be understood that movement of handle 12 is not exclusively lateral but rather defines an arc around the second rotational axis 55.

FIG. 6 shows a top surface of a fuel container 58 for a fuel-burning fireplace 10 where FIG. 6A shows a top view of the container top surface 41 having an aperture 40 therein. The aperture 40 can be made by cutting three side of an essentially rectangular shape in the top surface and thereafter bending the fourth side toward an inside of the container (not shown). The flap 60 is created when the top surface is bent toward the inside of the container. Flap apertures 62 can be made either prior to or after cutting the three sides. It will be understood that any top surface 41 of a fuel container 58 having a flap 60 directed therein that has flap apertures 62 will be effective for creating airflow turbulence causing movement (dancing) of the flame and slowing down combustion of the fuel for prolonging the life of the flame. The ultimate objective of the flap 60 is to provide an aesthetically pleasing flame 11 that will burn for a long period of time, thereby reducing the frequency of refilling the fuel container 58. The flap 60 can advantageously be the portion of the top surface 41 that is to become the aperture 40 but any other structure or method for providing a inwardly projecting flap 60 will have the desired effect. For example, an appropriate piece of metal welded onto the top surface would be considered a flap. In an embodiment where the flap is the bent portion of the aperture as explained above, it is advantageous to place the first row of flap apertures exactly on the bend of the flap (as shown in FIG. 6C). This flap aperture location is very important because even when the ethanol level reaches the upper rim such that the lower flap apertures are submerged in liquid fuel, fumes and gases generated inside the container are still able to escape the container through the first row of flap apertures. In absence of the first row (bend-level) flap apertures, there exists a risk of spontaneous ignition (i.e. poufs) of the gas pockets when lighting the unit.

FIG. 6B shows a side view of the top surface showing multiple (3) flaps bent and extending downward toward an inside of a container. Experiments were carried out to determine the optimal configuration of flap apertures 62 for producing the desired effect. Applicant has discovered that flap apertures 62 can have a diameter between 2 and 10 mm, representing between 10 and 80% of the total surface area of the flap 60. Preferably, the flap aperture 62 diameter can be between 3 and 8 mm and representing between 15% and 60% of the total surface area of the flap 60. Even more preferably, the flap aperture 62 diameter can be between 4 and 6 mm and representing between 20% and 40% of the total surface area of the flap 60. It is understood that although flap apertures 62 are shown as being circular and having a certain diameter, a square or any other shape having a certain diagonal and covering a similar predetermined percentage of the flap will be effective in achieving the two objectives defined above. Important considerations for the flap apertures 62 are size, number and location and to a lesser degree, shape. In some embodiments, such as that shown partially in FIG. 6B, the fuel container (not shown) is separated into several independent/isolated containers where dividing walls inside the container reach the top surface of the container. The purpose of dividing the container into many isolated smaller containers is to help “even out” the flame throughout the burner, especially when the burner system is not completely level. In such embodiments, the flap 60 is divided into the same number of sections by providing flap gaps 67 that allow folding the individual flap section into the individual isolated container without impinging on the dividing walls.

FIG. 6C shows a top perspective view of a container top surface 41 with the flap 60 extending downward into the container (not shown) and flap apertures 62 defined therein.

FIG. 7 shows and embodiment of an adjustable shutter 42 for a burner system 20 having a shutter adjustment whereby a translational movement of a handle 12 in a longitudinal 70 direction also moves the shutter 42 in a longitudinal 70 direction, with respect to the fireplace. In this embodiment, the fuel container 58 has a rectangular aperture extending in a lateral 72 orientation and a connecting member 46 for connecting the handle 12 to the shutter 42 for variably adjusting the shutter (and flame size). The connecting member 46 is secured to the two lateral extremities 48 of the fuel container 58 and rests on a translation track 74 that supports the connecting member 46 and handle 12.

It will be appreciated that other mechanisms can allow for movement of a handle to cause a balanced movement of the shutter. For example, the ends of the shutter can be threaded and adapted to mate with a threaded connecting member such that rotation of the handle/knob can cause movement of the shutter over the aperture. In such an embodiment, three full rotations of the knob can cause the shutter to go from an aperture “covered” position to an aperture “exposed” position.

FIG. 8 shows the movement of air in the convection chamber 85 of a fuel burning fireplace 10 according to and embodiment of the present invention. The convection chamber 85 is generally defined by the outer surface of the inner housing and the inner surface of the outer housing 14. The outer housing 14 has air intake apertures on its bottom surface 35, thereby allowing colder air 81 to enter the fireplace 10 and move upwardly along the convection chamber 85 to exit at the air outflow apertures 18 located at a top of the fireplace. When the fireplace is active and thus generating heat, a natural movement of air draws in colder air 81 (room temperature air) from the bottom, warms the colder air by heat exchange with the outside surface of the inner housing as the air moves upwardly along the convection chamber 85 to the air outflow apertures 18 at or near a top surface of the fireplace, where warmer air is released. The convection process occurring in the convection chamber 85 allows for warm air to exit from the air outflow apertures but also allows to cool the outer surface of the fireplace. Warm air also exits the fireplace above the protective glass 19 directly from the inner chamber.

FIG. 9 shows a partially exploded view of the various parts of a fuel-burning fireplace 10 according to another embodiment of the present invention. The parts shown are the burner system 20, the housing which comprises the inner housing side wall 32 of the inner housing and the outer housing 14, the protective glass 19 and the glass receiving members 16.

Some of the advantages of the adjustable burner system of the present invention is that, being secured to the two extremities 48 of the fuel container allows for a mechanically balanced movement of the burner shutter 42. Furthermore, design of the convection chamber allows air-cooling of the outer surface, making it less likely that a user of the fireplace will suffer burns by touching the unit. Due to the natural tendency of hot air to rise, the design of the convection chamber having an air intake at the bottom and air outflow at the top is advantageous.

Applicant has also discovered that, due to the frequent thermal cycling of the fireplace unit, it is advantageous to provide a protective glass 19 that need not be drilled, punctured or further altered in order to provide “mounting/securing” holes therein, thereby preserving structural integrity of the glass. This screwless attachment mechanism is achieved by providing an essentially U-shaped glass receiving member that is designed as a slot to receive and secure the glass.

It will be understood that, although in the illustrated embodiments presented herein, the handle is located in the front of the fireplace, a side or top handle would still be accessible from the front and, for free standing fireplaces, a back handle could be considered a front handle when looking from the opposite side.

It will be understood that a fireplace is generally understood, for the purposes herein, to include table units and any free-standing or mounted heat/flame generating devices.

While preferred embodiments have been described above and illustrated in the accompanying drawings, it will be evident to those skilled in the art that modifications may be made without departing from this disclosure. Such modifications are considered as possible variants comprised in the scope of the disclosure. 

What is claimed is:
 1. A burner system for a fuel-burning fireplace comprising: a fuel container having at top surface with at least one aperture for combusting said fuel contained therein; and an adjustable flame regulator for regulating a size of said flame comprising: a shutter for covering said aperture, said shutter being variably adjustable between a first position wherein said aperture is covered and a second position wherein said aperture is exposed; a handle extending from said burner system for variably adjusting said shutter; and a connecting member for connecting said shutter to said handle, said connecting member being functionally connected to at least two extremities of said shutter; wherein movement of said handle allows a balanced movement of said shutter over said aperture.
 2. The burner system of claim 1, wherein said shutter rests on said top surface and slides across said aperture.
 3. The system of claim 1, wherein said connecting member is rotatably mounted to at least two extremities of said container and rotates around a first rotational axis.
 4. The system of claim 1, wherein said connecting member is configured such that a lateral movement of said handle with respect to said fireplace causes a longitudinal movement of said shutter.
 5. The system of claim 1, wherein said shutter has apertures near its extremities for receiving an extension of said connecting member, said extension extending from said connecting member at said first rotational axis.
 6. The system of claim 1, wherein said handle is rotatably mounted to said fireplace at a second rotational axis and wherein said second rotational axis is orthogonal to said first axis and movement of said handle causes a rotation of said connecting member around said second rotational axis.
 7. The system of claim 1, wherein said handle is rotatably coupled to said connecting member and wherein a rotation of said handle causes threaded extremities of said shutter to interact with threaded extremities of said aperture.
 8. The system of claim 1, further comprising a coverplate for covering said container and said shutter.
 9. The system of claim 8, wherein said coverplate comprises slits for allowing air intake at a site of combustion and cooling of said coverplate.
 10. The system of claim 8, further comprising a coverplate aperture at an extremity of said coverplate for receiving said connecting member extension, wherein said shutter is configured to be adjustable by moving said connecting member extension.
 11. The system of claim 1, wherein said fuel is in liquid form.
 12. The system of claim 1, wherein said fuel is ethanol.
 13. A fuel-burning fireplace comprising: a burner for combusting a liquid fuel contained therein; an inner housing for receiving said burner and heat generated therefrom; and an outer housing fitting around said inner housing and defining a convection chamber between said inner housing and said outer housing; wherein said chamber comprises air intake apertures on a bottom for receiving colder air into said chamber and air outflow apertures on a top for releasing warmer air form said chamber while cooling a surface of said outer housing.
 14. The fireplace as claimed in claim 13, further comprising one or more glass receiving member extending from said outer housing, said glass receiving member comprising a slot for receiving and securing a protective glass without making holes in said glass.
 15. A burner for a liquid fuel burning fireplace comprising: a fuel container having a top surface with an aperture for allowing a combustion of fuel contained therein and generating a flame; a flap adjacent and along a side of said aperture and extending away from said top surface toward an inside of said container; said flap having flap apertures therein configured to slow combustion of said fuel and animate said flame by creating turbulence.
 16. The burner as claimed in claim 15, wherein said flap is continuous with said top surface and represents a portion of said top surface that was in place of said aperture prior to bending said flap.
 17. The burner of claim 16 wherein said flap further comprises a plurality of flap apertures along a bend line of said flap, said flap apertures for evacuating gaseous fuel accumulations when a level of said liquid fuel in said container is high.
 18. The burner of claim 15, wherein a diameter of said flap apertures is between 2 and 8 mm.
 19. The burner of claim 17, wherein a diameter of said flap apertures is between 4 and 6 mm.
 20. The burner of claim 15, wherein a surface area of said flap apertures is between 15% to 60% of a total surface area of said flap.
 21. The burner of claim 15, wherein a surface area of said flap apertures is between 20% to 40% of a total surface area of said flap.
 22. The burner of claim 15, wherein the top surface is a removable coverplate.
 23. The burner of claim 15, further comprising a dividing wall inside said fuel container for defining smaller partially isolated compartments. 